docs: def distance(self, xyz=(0.00, 0.00, 0.00)):
          """Computes Euclidean distance between atoms in
              self.df and a 3D point.
  
          Parameters
          ----------
          xyz : tuple (0.00, 0.00, 0.00)
              X, Y, and Z coordinate of the reference center for the distance
              computation
  
          Returns
          ---------
          pandas.Series : Pandas Series object containing the Euclidean
              distance between the atoms in the atom section and `xyz`.
  
          """
          return np.sqrt(np.sum(self.df[['x', 'y', 'z']]
                         .subtract(xyz, axis=1)**2, axis=1))